1. Field of the Invention
The present invention relates to a system for keeping safe runs of mobiles, and more particularly, it relates to a mobile run management system for attaining safe runs of mobiles by scanning a lane and keeping a safe distance between the mobiles such as automobiles on an expressway, a reserved road or the like. Throughout the specification and claims, the term "mobiles" indicate not only apparatuses such as automobiles, ships and airplanes for carrying human beings or cargos, but self-movable things such as human beings and other living things.
2. Description of the Background Art
One of the causes for traffic accidents on an expressway, a reserved road or the like is that no safe distance is kept between the vehicles. In order to keep safe runs of automobiles, a safe distance or no distance may be kept between the automobiles.
In order to keep a safe distance between automobiles, it is necessary to provide the vehicles with measuring means which can measure the distance therebetween in high accuracy and high reliability. Considering that the measuring means are provided on respective vehicles, such measuring means must be supplied at a low cost.
As the simplest method of keeping no distance between automobiles, on the other hand, the automobiles 300 and 302 may be coupled with each other by a coupler 304, as shown in FIG. 21. The number of the coupled automobiles is not restricted to two, as a matter of course. When such automobiles are coupled with each other, however, it is difficult for the plurality of coupled automobiles to draw the same trajectory since the road for the automobiles has no means corresponding to the rails on a railroad track.
There has been proposed a method of controlling tracking in a non-contact manner not by such mechanical coupling but by an electronic/communication technique. In this system, a transmitter is provided on a front part of an automobile 312 for detecting a radio or ultrasonic wave transmitted therefrom and reflected by a rear part of another automobile 310 running ahead thereby making non-contact tracking control. In such a non-contact tracking control method, however, measurement errors or errors following data processing exceeding an allowable range may result in an accident. At the moment, therefore, this system is impractical due to insufficient reliability.
After all, the most effective countermeasure against occurrence of an accident is to keep a safe distance between mobiles at present. Thus, development of a highly reliable mobile run management system is awaited. Such a run management system preferably can properly manage runs of mobiles in response to changes of various conditions such as the weather, the average speeds of the mobiles and the like. Further, the system is preferably free from regulation by the radio law or the like since the system is applied to an extremely long road or the like, while the mobiles can preferably utilize information related to runs thereof as much as possible. In addition, the mobiles, which may run at high speeds, can preferably receive information related to the positions and speeds thereof and whether or not the mobiles are present in a certain zone, to sufficiently follow the high speeds. Further, a system which can safely manage not only the distance between the mobiles on a certain lane but course changes by the mobiles on a plurality of lanes.